1. Field of the Invention
The present invention relates generally to a waterproofing system for relieving and eliminating water problems associated with the foundation of an existing building, and, more particularly, to a most preferred method for dealing with ground water problems in situations wherein a trench can be dug immediately adjacent an exterior surface of a foundation wall to expose its exterior surface.
2. Prior Art
Accepted conventional waterproofing techniques call for a trench to be dug carefully, usually by hand, immediately adjacent to the exterior surface of the foundation of a building to expose problematical wall portions, if not all of the foundation's exterior surface, for repair and treatment. The ditch is dug to a level that permits the building's footer drain tile system to be exposed for inspection, cleaning and repair. If the building has a basement floor, the ditch is dug to a level below that of the top of the basement floor of the building to expose and permit servicing of the building's footer drain tile system, and to assure that the footer drain tile is properly positioned below the level of the basement floor.
3. The Referenced U.S. Pat. No. 4,136,500
The disclosure of the referenced U.S. Pat. No. 4,136,500 is incorporated herein inasmuch as it presents the best and most accepted technique utilized in present-day practice for thoroughly repairing and waterproofing hollow foundation walls of an existing building, and for preventing the recurrence of ground water problems associated with hollow foundation walls of a building. The disclosure of the referenced U.S. Pat. No. 4,136,500 is also incorporated herein for its discussion of such techniques as are best employed in treating an exposed foundation with materials to diminish water penetrability, and of techniques that are preferably used in servicing and/or restructuring a footer drain tile system.
The referenced U.S. Pat. No. 4,136,500 relates to a method of overcoming the problem of water seeping into the basement of a dwelling or other building structure, whereby (1) hollow foundation walls are treated to fill its hollow spaces, especially hollow spaces in the vicinity of cracks or other structural damage or deterioration, (2) the footer drain line system of the building is serviced and restructured if need be to put it in proper form for trouble-free operation, (3) clean-outs are provided at spaced locations around the foundation for future checking and servicing of the footer drain line system, and (4) porous reservoirs are formed from particulate material such as stone in lower portions of the trenches or tunnels which have been dug about the foundation of the building. The porous reservoirs provide a system of open passages for ducting water to the footer drain line system, and for providing regions where water may temporarily accumulate harmlessly in a situation of heavy rainfall or backup of the storm drain line which serves the building.
The referenced U.S. Pat. No. 4,136,500 also discusses the advantages which can result from constructing a manhole at the juncture of the footer drain line system and the storm drain line that services a dwelling. In some situations it is desirable to install a check valve in the storm drain line at the location of the manhole to prevent water from backing up in the storm drain line and into the dwelling's footer drain line system. In other situations, it is desirable to have the footer drain line system discharge directly into the manhole, and to utilize a sump pump to transfer water from the manhole to the storm drain line.
While the waterproofing system disclosed in the referenced U.S. Pat. No. 4,136,500 continues to represent the most preferred approach to take in dealing with waterproofing problems where hollow building walls can be accessed by digging trenches immediately adjacent their exterior surfaces, there are situations where the digging of a trench immediately adjacent the exterior surface of a foundation wall is unduly expensive and/or would unacceptably require the removal or destruction of valuable foundation plantings or existing structures. Such a situation is addressed by the invention of the referenced U.S. Pat. No. 4,523,875.
4. The Referenced U.S. Pat. No. 4,523,875
The invention of the referenced U.S. Pat. No. 4,523,875 application relates to the use of an auxiliary drain line which is laid in a trench that extends about lower portions of the foundation of an existing building, but at locations preferably spaced several feet from the foundation. The newly laid auxiliary drain line is formed of perforate material (preferably perforated vitreous clay tile of about twelve inches in length laid end-to-end but spaced apart by distances within the range of about 1/16 inch to about 1/4 inch) which admits surrounding ground water, and is connected to a storm drain line that serves the building so that water which enters the auxiliary drain line is discharged into the storm drain line.
The invention of the referenced U.S. Pat. No. 4,523,875 application further calls for a porous reservoir to be formed in the trench about the auxiliary drain line (1) to aid in ducting ground water to the auxiliary drain line, (2) to eliminate ground water pressure buildup in the vicinity of the foundation wall, and (3) to provide a ground water reservoir where water can harmlessly and temporarily accumulate in the situation of a heavy rainfall or backup of the storm drain line that serves the building. The presence of the porous reservoir that is defined by the stone serves to keep clay and other soils away from the foundation wall so that no medium is present adjacent the foundation wall that can retain ground water and enable a buildup of ground water pressure on the foundation wall. The reservoir also minimizes dampness of the foundation wall because, since ground water will travel under the influence of gravity downwardly through the open passages and interstices of the reservoir rather than horizontally across the reservoir, ground water does not tend to travel toward and come to rest adjacent the foundation wall, as would otherwise be the case if soil or clay were packed solidly against the outer surface of the foundation wall.
In situations where the building has a basement, the invention of the referenced U.S. Pat. No. 4,523,875 application calls for an auxiliary drain line to be laid in the trench at a level below the top of the basement floor of the building. In the event the storm drain line is found to be positioned too high to permit the auxiliary drain line to discharge into it properly, (1) a manhole is constructed, (2) the auxiliary drain line is connected to discharge into the manhole, (3) a sump pump is provided in the manhole for transferring water from the manhole to the storm drain line. Branch lines may be installed in short underground tunnels to connect the new auxiliary drain line with an existing footer drain line system which surrounds the foundation of the building. Additionally, the building's downspouts may be rerouted to the auxiliary drain line as may be needed to bypass clogged storm drain line sections. Moreover, the building's downspouts are preferably provided with specially configured leaf traps which may be cleaned out above ground level.